The present invention, in some embodiments thereof, relates to medical devices, and in particular to balloon catheters applicable for treating blood vessels.
Balloon catheters are well known and used in treating various conditions in blood vessels. Two main types of balloon catheters in that area are dilatation balloon catheter, used to treat narrowed or stenotic portions of the vessel and recover flow (e.g., angioplasty balloon catheters), and occlusion balloon catheters, used to temporarily block flow out of a vessel segment while infusing fluid (e.g., medicament, contrast enhancer or flushing material) therein.
Some balloon catheters have at least three parallel functions, including: balloon inflation, travel over a guide wire, and infusion or dispersion of fluids therethrough. Such balloon catheters often include at least three lumens passing there along, including an inflation lumen, a guidewire lumen and an infusion lumen, correspondingly. In some occasions it is suggested to treat a blood vessel with a balloon catheter comprising an infusion exit opening located proximally to the balloon member, particularly if the balloon member is used for occlusion at least partially during infusion. U.S. Pat. No. 7,182,755 describes a use of an occlusion balloon catheter with a proximal infusion opening for treating hemodialysis vascular access. U.S. Pat. No. 5,368,567 describes a dilatation balloon catheter with a proximal infusion opening. The disclosures of both patents are fully incorporated herein by reference.
In some such occasions, minimization of catheter's lumens cross-sections is advantageous. In one example, there may be a need for a small diameter catheter for intraluminal passage (e.g., 3 F to 5 F) so it is more complex to introduce three lumens. In a second example, there may be a need to fortify the catheter shaft for high pressure dilatations (as in vascular access recanalization in certain anatomies), so it may be advantageous to decrease overall lumens size in a certain shaft diameter.